It sounds like you are in a nice spot where you have options moving forward with investing, (congrats).

We have three potential options.The first option is for me to completely owner-finance his purchase.

Your options are greater ahead of the transaction as opposed to when the transaction has already been entered into.Best of luck to you!

If you're considering purchasing under a business name, consult a CPA or attorney for setup and financing options.

While I’ve considered cash-out refinancing or HELOCs, the high rates make these options less appealing.I’m debating between using cash to acquire more SFRs or diversifying into mixed-use retail properties.

I would finish 4/6 rooms down there with proper egress and optional ventilation.

Reach out if you would like to compare options or revenue potential for different homes and communities. 

@Matthew Posteraro I'm a big fan of starting with the 5% options. 

My view is there is more protection on a wrap than a sub to and with the right disclosures and underwriting can be an alternative option. 

It’s definitely smart to evaluate the tax and cost implications of your funding options.